To address this issue of the response of amblyopia to treatment in children 7 years and older, the Pediatric Eye Disease Investigator Group (PEDIG) conducted a randomized trial of 507 patients (aged 7 to <18 years) with amblyopic eye visual acuity ranging from 20/40 to 20/400. Patients were provided with optimal optical correction and then randomized to a Treatment Group (2 to 6 hours per day of prescribed patching of the sound eye combined with near visual activities for all patients plus atropine one drop per day in the sound eye for 7 to <13 year olds) or an Optical Correction Group (optical correction alone). Patients whose amblyopic eye acuity improved 10 or more letters (2 lines) by 24 weeks were considered responders. In the 7 to <13 year olds (N=404), 53% of the Treatment Group were responders compared with 25% of the Optical Correction Group (P<0.001). In the 13 to <18 year olds (N=103), the responder rates were 25% and 23% respectively overall (adjusted P=0.22), but 47% and 20% respectively among patients not previously treated with patching and/or atropine for amblyopia (adjusted P=0.03). Most patients, including responders, were left with a residual visual acuity deficit.